Acne vulgaris (acne) is the formation of comedones, papules, pustules, nodules, and/or cysts as a result of obstruction and inflammation of pilosebaceous units (hair follicles and their accompanying sebaceous gland). It most often affects adolescents. Diagnosis is by examination. Treatment is a variety of topical and systemic agents intended to reduce sebum production, bacterial counts, and inflammation and to normalize keratinization.


The most common trigger is puberty, when surges in androgen stimulate sebum production and hyperproliferation of keratinocytes. Other triggers include hormonal changes that occur with pregnancy or the menstrual cycle; occlusive cosmetics, cleansers, lotions, and clothing; and high humidity and sweating. Associations between acne exacerbation and diet, inadequate face washing, masturbation, and sex are unfounded. Some studies suggest a possible association with milk products and high-glycemic diets. Acne may abate in summer months because of sunlight’s anti-inflammatory effects.

Signs and symptoms:

Cystic acne can be painful; other types cause no physical symptoms but can be a source of significant emotional distress. Lesion types frequently coexist at different stages.

Comedones appear as whiteheads or blackheads. Whiteheads (closed comedones) are flesh-colored or whitish palpable lesions 1 to 3 mm in diameter; blackheads (open comedones) are similar in appearance but with a dark center.


  • Assessment for contributing factors (eg, hormonal, mechanical, or drug-related)
  • Determination of severity (mild, moderate, severe)
  • Assessment of psychosocial impact